Lions' Odd Fake Field Goal

After stopping a Detroit Lions' fake field goal attempt, down 23-27, the Pittsburgh Steelers went on to score two unanswered touchdowns - clearly a product of momentum - and win the game 37-27. When the Lions faked the field goal, I was a little bit baffled. Normally, inside the 10 or so it makes sense to go for it because even with a failure, opposing offenses are pinned so deep in their own territory - depending on distance-to-go. 4th-and-5, with vertical space restricted at the 10-yard line, is not an easy conversion; it converts league-wide around 36%. Based purely on efficiency (not including time remaining or score differential), a field goal results in greater return (+0.16 EP over going for it). It's not a huge difference, as the break even point is only 39% conversion probability.

But, in this case, the Lions were up four and a field goal goes a long way toward winning the game. We see it again: being up four is suboptimal toward the end of the game. Here, with a made field goal (which converts at 94% from the 10), the Lions' win probability increases to 82%. With a successful conversion, that increases to 87% making the break-even point an unrealistic 66%. Fakes can increase success rates due to their surprise nature (five-yards to go is successful around 46% on a fake, but the lack of vertical room would diminish that probability). And often, fakes occur because of a specific game plan where the offense recognizes a trend or vulnerability in the defense. Jim Schwartz stuck by his "gutsy" decision, and maybe he had seen something to lead him to believe his conversion probability was much higher (or believed his win probability was in fact much lower than a league-average baseline).

While I do not think momentum from the failed conversion had anything to do with the Lions ultimate loss, the decision itself was a little bit puzzling given the game situation. After a fumble on the fake attempt, the Lions' win probability was at 70%. Big Ben and the Steelers then drove 97 yards down the field for the go-ahead touchdown.

Keith Goldner is the Chief Analyst at numberFire.com - The leading fantasy sports analytics platform - and creator of Drive-By Football.  Follow him on twitter @drivebyfootball or check out numberFire on Facebook.